Hi Marc, On 13/06/16 10:10, Marc Zyngier wrote: > Hi Jon, > > On 07/06/16 16:12, Jon Hunter wrote: >> Add a platform driver to support non-root GICs that require runtime >> power-management. Currently, only non-root GICs are supported because >> the functions, smp_cross_call() and set_handle_irq(), that need to >> be called for a root controller are located in the __init section and >> so cannot be called by the platform driver. >> >> The GIC platform driver re-uses many functions from the existing GIC >> driver including some functions to save and restore the GIC context >> during power transitions. The functions for saving and restoring the >> GIC context are currently only defined if CONFIG_CPU_PM is enabled and >> to ensure that these functions are always defined when the platform >> driver is enabled, a dependency on CONFIG_ARM_GIC_PM (which selects the >> platform driver) has been added. >> >> In order to re-use the private GIC initialisation code, a new public >> function, gic_of_init_child(), has been added which calls various >> private functions to initialise the GIC. This is different from the >> existing gic_of_init() because it only supports non-root GICs (ie. does >> not call smp_cross_call() is set_handle_irq()) and is not located in >> the __init section (so can be used by platform drivers). Furthermore, >> gic_of_init_child() dynamically allocates memory for the GIC chip data >> which is also different from gic_of_init(). >> >> There is no specific suspend handling for GICs registered as platform >> devices. Non-wakeup interrupts will be disabled by the kernel during >> late suspend, however, this alone will not power down the GIC if >> interrupts have been requested and not freed. Therefore, requestors of >> non-wakeup interrupts will need to free them on entering suspend in >> order to power-down the GIC. >> >> Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx> >> --- >> drivers/irqchip/Kconfig | 6 ++ >> drivers/irqchip/Makefile | 1 + >> drivers/irqchip/irq-gic-pm.c | 184 ++++++++++++++++++++++++++++++++++++++++ >> drivers/irqchip/irq-gic.c | 38 ++++++++- >> include/linux/irqchip/arm-gic.h | 6 ++ >> 5 files changed, 232 insertions(+), 3 deletions(-) >> create mode 100644 drivers/irqchip/irq-gic-pm.c >> >> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig >> index fa33c50b0e5a..5495a5ba8039 100644 >> --- a/drivers/irqchip/Kconfig >> +++ b/drivers/irqchip/Kconfig >> @@ -8,6 +8,12 @@ config ARM_GIC >> select IRQ_DOMAIN_HIERARCHY >> select MULTI_IRQ_HANDLER >> >> +config ARM_GIC_PM >> + bool >> + depends on PM >> + select ARM_GIC >> + select PM_CLK >> + >> config ARM_GIC_MAX_NR >> int >> default 2 if ARCH_REALVIEW >> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile >> index 38853a187607..bd0257e0aab6 100644 >> --- a/drivers/irqchip/Makefile >> +++ b/drivers/irqchip/Makefile >> @@ -24,6 +24,7 @@ obj-$(CONFIG_ARCH_SUNXI) += irq-sun4i.o >> obj-$(CONFIG_ARCH_SUNXI) += irq-sunxi-nmi.o >> obj-$(CONFIG_ARCH_SPEAR3XX) += spear-shirq.o >> obj-$(CONFIG_ARM_GIC) += irq-gic.o irq-gic-common.o >> +obj-$(CONFIG_ARM_GIC_PM) += irq-gic-pm.o >> obj-$(CONFIG_REALVIEW_DT) += irq-gic-realview.o >> obj-$(CONFIG_ARM_GIC_V2M) += irq-gic-v2m.o >> obj-$(CONFIG_ARM_GIC_V3) += irq-gic-v3.o irq-gic-common.o >> diff --git a/drivers/irqchip/irq-gic-pm.c b/drivers/irqchip/irq-gic-pm.c >> new file mode 100644 >> index 000000000000..4cbffba3ff13 >> --- /dev/null >> +++ b/drivers/irqchip/irq-gic-pm.c >> @@ -0,0 +1,184 @@ >> +/* >> + * Copyright (C) 2016 NVIDIA CORPORATION, All Rights Reserved. >> + * >> + * This program is free software; you can redistribute it and/or modify >> + * it under the terms of the GNU General Public License version 2 as >> + * published by the Free Software Foundation. >> + * >> + * This program is distributed in the hope that it will be useful, >> + * but WITHOUT ANY WARRANTY; without even the implied warranty of >> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the >> + * GNU General Public License for more details. >> + * >> + * You should have received a copy of the GNU General Public License >> + * along with this program. If not, see <http://www.gnu.org/licenses/>. >> + */ >> +#include <linux/module.h> >> +#include <linux/clk.h> >> +#include <linux/of_device.h> >> +#include <linux/of_irq.h> >> +#include <linux/irqchip/arm-gic.h> >> +#include <linux/platform_device.h> >> +#include <linux/pm_clock.h> >> +#include <linux/pm_runtime.h> >> +#include <linux/slab.h> >> + >> +struct gic_clk_data { >> + unsigned int num_clocks; >> + const char *const *clocks; >> +}; >> + >> +static int gic_runtime_resume(struct device *dev) >> +{ >> + struct gic_chip_data *gic = dev_get_drvdata(dev); >> + int ret; >> + >> + ret = pm_clk_resume(dev); >> + if (ret) >> + return ret; >> + >> + /* >> + * On the very first resume, the pointer to the driver data >> + * will be NULL and this is intentional, because we do not >> + * want to restore the GIC on the very first resume. So if >> + * the pointer is not valid just return. >> + */ >> + if (!gic) >> + return 0; >> + >> + gic_dist_restore(gic); >> + gic_cpu_restore(gic); >> + >> + return 0; >> +} >> + >> +static int gic_runtime_suspend(struct device *dev) >> +{ >> + struct gic_chip_data *gic = dev_get_drvdata(dev); >> + >> + gic_dist_save(gic); >> + gic_cpu_save(gic); >> + >> + return pm_clk_suspend(dev); >> +} >> + >> +static int gic_get_clocks(struct device *dev, const struct gic_clk_data *data) >> +{ >> + struct clk *clk; >> + unsigned int i; >> + int ret; >> + >> + if (!dev || !data) >> + return -EINVAL; >> + >> + ret = pm_clk_create(dev); >> + if (ret) >> + return ret; >> + >> + for (i = 0; i < data->num_clocks; i++) { >> + clk = of_clk_get_by_name(dev->of_node, data->clocks[i]); >> + if (IS_ERR(clk)) { >> + dev_err(dev, "failed to get clock %s\n", >> + data->clocks[i]); >> + ret = PTR_ERR(clk); >> + goto error; >> + } >> + >> + ret = pm_clk_add_clk(dev, clk); >> + if (ret) { >> + dev_err(dev, "failed to add clock at index %d\n", i); >> + clk_put(clk); >> + goto error; >> + } >> + } >> + >> + return 0; >> + >> +error: >> + pm_clk_destroy(dev); >> + >> + return ret; >> +} >> + >> +static int gic_probe(struct platform_device *pdev) >> +{ >> + struct device *dev = &pdev->dev; >> + const struct gic_clk_data *data; >> + struct gic_chip_data *gic; >> + int ret, irq; >> + >> + data = of_device_get_match_data(&pdev->dev); >> + if (!data) { >> + dev_err(&pdev->dev, "no device match found\n"); >> + return -ENODEV; >> + } >> + >> + irq = irq_of_parse_and_map(dev->of_node, 0); >> + if (!irq) { >> + dev_err(dev, "no parent interrupt found!\n"); >> + return -EINVAL; >> + } >> + >> + ret = gic_get_clocks(dev, data); >> + if (ret) >> + goto irq_dispose; >> + >> + pm_runtime_enable(dev); >> + >> + ret = pm_runtime_get_sync(dev); >> + if (ret < 0) >> + goto rpm_disable; >> + >> + ret = gic_of_init_child(dev, &gic, irq); >> + if (ret) >> + goto rpm_put; >> + >> + platform_set_drvdata(pdev, gic); >> + >> + pm_runtime_put(dev); >> + >> + dev_info(dev, "GIC IRQ controller registered\n"); >> + >> + return 0; >> + >> +rpm_put: >> + pm_runtime_put_sync(dev); >> +rpm_disable: >> + pm_runtime_disable(dev); >> + pm_clk_destroy(dev); >> +irq_dispose: >> + irq_dispose_mapping(irq); >> + >> + return ret; >> +} >> + >> +static const struct dev_pm_ops gic_pm_ops = { >> + SET_RUNTIME_PM_OPS(gic_runtime_suspend, >> + gic_runtime_resume, NULL) >> +}; >> + >> +static const char * const gic400_clocks[] = { >> + "clk", >> +}; >> + >> +static const struct gic_clk_data gic400_data = { >> + .num_clocks = ARRAY_SIZE(gic400_clocks), >> + .clocks = gic400_clocks, >> +}; >> + >> +static const struct of_device_id gic_match[] = { >> + { .compatible = "nvidia,tegra210-agic", .data = &gic400_data }, >> + {}, >> +}; >> +MODULE_DEVICE_TABLE(of, gic_match); >> + >> +static struct platform_driver gic_driver = { >> + .probe = gic_probe, >> + .driver = { >> + .name = "gic", >> + .of_match_table = gic_match, >> + .pm = &gic_pm_ops, >> + } >> +}; >> + >> +builtin_platform_driver(gic_driver); >> diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c >> index 141ea5801784..57423f3b218b 100644 >> --- a/drivers/irqchip/irq-gic.c >> +++ b/drivers/irqchip/irq-gic.c >> @@ -75,7 +75,7 @@ struct gic_chip_data { >> void __iomem *raw_dist_base; >> void __iomem *raw_cpu_base; >> u32 percpu_offset; >> -#ifdef CONFIG_CPU_PM >> +#if defined(CONFIG_CPU_PM) || defined(CONFIG_ARM_GIC_PM) >> u32 saved_spi_enable[DIV_ROUND_UP(1020, 32)]; >> u32 saved_spi_active[DIV_ROUND_UP(1020, 32)]; >> u32 saved_spi_conf[DIV_ROUND_UP(1020, 16)]; >> @@ -528,7 +528,7 @@ int gic_cpu_if_down(unsigned int gic_nr) >> return 0; >> } >> >> -#ifdef CONFIG_CPU_PM >> +#if defined(CONFIG_CPU_PM) || defined(CONFIG_ARM_GIC_PM) >> /* >> * Saves the GIC distributor registers during suspend or idle. Must be called >> * with interrupts disabled but before powering down the GIC. After calling >> @@ -1296,6 +1296,34 @@ error: >> return -ENOMEM; >> } >> >> +int gic_of_init_child(struct device *dev, struct gic_chip_data **gic, int irq) > > I got this: > > WARNING: drivers/built-in.o(.text+0x2464): Section mismatch in reference from the function gic_of_init_child() to the function .init.text:gic_of_setup() > The function gic_of_init_child() references > the function __init gic_of_setup(). > This is often because gic_of_init_child lacks a __init > annotation or the annotation of gic_of_setup is wrong. Ugh! A lot of the changes were to avoid these section mismatches. Somehow I missed that one :-( > I've fixed it locally by making the function __init. So gic_of_init_child() cannot be __init because it is called by the driver. If you do this you should get ... WARNING: drivers/irqchip/built-in.o(.text+0x2314): Section mismatch in reference from the function gic_probe() to the function .init.text:gic_of_init_child() The function gic_probe() references the function __init gic_of_init_child(). This is often because gic_probe lacks a __init annotation or the annotation of gic_of_init_child is wrong. The correct fix is ... diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c index 57423f3b218b..1de07eb5839c 100644 --- a/drivers/irqchip/irq-gic.c +++ b/drivers/irqchip/irq-gic.c @@ -1272,7 +1272,7 @@ static bool gic_check_eoimode(struct device_node *node, void __iomem **base) return true; } -static int __init gic_of_setup(struct gic_chip_data *gic, struct device_node *node) +static int gic_of_setup(struct gic_chip_data *gic, struct device_node *node) { if (!gic || !node) return -EINVAL; Cheers Jon -- nvpublic -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
